What's the story after F1 Testing? Mark Hughes explains Mercedes' race against time for Bahrain GP

If the competitive order between the teams in the season-opening Bahrain Grand Prix next week is as it was in testing at the same track last week, then we're in for a shake-up.

Mercedes is in a race against time to uncover the flaws that were making its new W12 such a difficult drive, with what both Lewis Hamilton and Valtteri Bottas described as an unstable and unforgiving rear end.

Red Bull meanwhile, benefitting from the double whammy of a significantly improved and shrunken Honda power unit and a more driveable-looking chassis than last year, look in the ascendancy.

Max Verstappen was fastest on the final day by as much as 0.7s when adjusting for the tyre differences.

So can we trust the testing times?

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Mercedes' Lewis Hamilton brought out the red flag during the morning session of testing on day 2 in Bahrain, after spinning his car at turn 13, beaching the W12 in the process

The test times need to be taken with an even larger pinch of salt than normal this year because of the compressed three-day timetable around a circuit which varied enormously in grip between the heat of the afternoon and the cool dusk, meaning it was only in the last 90 minutes of running each day that the really quick times would be set.

The wind was also powerful and variable, as you will have seen from the trackside footage, but the factor probably muddying the waters most of all was that most teams did not do full race simulations - as there simply wasn't enough time to do those as well as all the other experiments they wished to make.

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Full race simulations are when you can guarantee that the cars are running with very similar fuel loads, as they need the tanks near-full at the beginning to complete the sim. Only Ferrari and AlphaTauri did full race runs, so leaving a greater question mark than usual against the times set by most.

But even a difference in fuel weight would not explain why the Mercedes was visibly a handful - oversteering excessively mid-corner.

There was clearly something amiss.

Is F1 finally about to get its big contest?

So if we take the Mercedes out of the equation, the gap between Red Bull and the others - which lined up very closely-matched in the order of AlphaTauri, Ferrari and McLaren - was very much in line with what we saw last year: a gap of around 0.7s from Red Bull back to the 'best of the rest' bunch, with Ferrari possibly slightly more competitive than in 2020.

Aston Martin looked like it was potentially in that bunch - Lance Stroll set third-quickest time on the middle day - but the car was sidelined when the track was at its fastest in the final day.

Alpine appeared slightly adrift of that pack but well clear of the same three teams which brought up the rear last year - Alfa Romeo, Williams and Haas.

In other words, it's Mercedes which is the anomaly.

Meanwhile, both Verstappen and Sergio Perez racked up lap after lap in an RB16B which looked almost planted to the track. So, has the tipping point been reached? Can Mercedes be thwarted in chasing a clean sweep of titles in this era before the all-new regulations of next year?

If Red Bull's form in testing was not a desert mirage, then even if Mercedes does identify and correct its specific problem, it looks like we just might have the big contest F1 has been anticipating for far too long: Lewis Hamilton vs Max Verstappen in equal cars, the king and pretender.

It would be just as disappointing if the '21 season turned out to be one of Red Bull dominance rather than Mercedes. Let's hope that with a Mercedes aero glitch corrected, the two cars are near-enough equal and everything then focusses upon these two extraordinary performers.

Personally, I have not the slightest preference for which of them might come out on top in such a contest - only that it is a genuine contest which the best man may win.

But the passionate following of the fans on both sides in such a contest would add an even greater element to the season.

F1 would be the winner.